The disclosure relates to a method of forming semiconductor devices on a semiconductor wafer. More specifically, the disclosure relates to etching a stack in the formation of memory.
In forming semiconductor devices, etch layers may be etched to form memory holes or lines. Some semiconductor devices may be formed by etching a stack of bilayers of silicon oxide (oxide) and silicon nitride (nitride) (ONON). Such stacks may be used in memory applications, such as in forming dynamic random access memory (DRAM) and three dimensional “negative and” gates (3D NAND). The background description provided herein is for the purposes of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.